Cassini-Huygens Mission to Saturn Overview

Slide 1: Cassini-Huygens Mission to Saturn Overview QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture.

Slide 2: JPL Overview

Slide 3: NASA’s Jet Propulsion Laboratory, managed by the California Institute of Technology, is the world leader in robotic exploration of the solar system. http://photojournal.jpl.nasa.gov

Slide 4: Mission Overview

Slide 5: Huygens and Cassini The Scientists and the Machines Giovanni Domenico Cassini Christiaan Huygens (1625-1712), Italo-French (1629-1695) Dutch astronomer, who discovered scientist, who several of Saturn’s satellites: discovered the true Iapetus, Rhea, Tethys and nature of Saturn’s Dione. In 1675, he rings, and in 1655, discovered what is today Titan called “Cassini Division” the gap in-between the two main rings of Saturn

Slide 6: Cassini Orbiter & Huygens Probe

Slide 7: Launched on October 15, 1997 from KSC QuickTime™ and a YUV420 codec decompressor 7 year cruise on are needed to see this picture. VVEJGA trajectory

Slide 8: Cassini Spacecraft Cassini Spacecraft Specs • Height: 6.8 m (22 ft) • Diameter: 4 m (13 ft) • Mass: 2125 kg (2.8 tons) (fueled+probe): 5700 kg (6 tons) • Power: 700 Watts at SOI • .5 GB recorder • Huygens Probe: 320 kg (~700 lbs) Cassini Instruments: Magnetospherie and Plasma Science (MAPS) Optical Remote Sensing (ORS) CDA: Cosmic Dust Analyzer CIRS: Composite Infrared Spectrometer INMS: Ion and Neutral Mass Spectrometer ISS: Imaging Science Subsystem MAG: Dual Technique Magnetometer UVIS: Ultraviolet Imaging Spectrograph MIMI: Magnetospheric Imaging Instrument VIMS: Visual and Infrared mapping Spectrometer RPWS: Radio and Plasma Wave Science Microwave Remote Sensing RADAR: Cassini Radar RSS: Radio Science Subsystem

Slide 10: Cost • Cassini total cost $3 billion – $2.5 B NASA for Cassini, $0.5 B ESA for Huygens – Spread over ~20 y -> $150 M/y – Cassini 0.5% of NASA annual budget ($16.8 B) • NASA annual budget $16.8 B – 1.7% of U.S. discretionary spending ($982 B) – 0.6% total U.S. budget ($2800 B)

Slide 12: Tour Overview 4 year Prime Mission – 75 orbits – 45 targeted Titan flybys – 8 targeted icy satellite flybys 5 Science Objectives QuickTime™ and a Animation decompressor Titan – are needed to see this picture. Saturn – Rings – Icy Satellites – Magnetosphere – Tour (Petal) movie

Slide 13: #1: Huygens on Titan

Slide 14: Why Titan? • Diameter – 5150km; larger than Mercury and Pluto • Only planetary satellite with a dense atmosphere • Surface: P: 1.5 X Earth’s; T: 94 K (-179 C) • Composition – Nitrogen (N2); Methane (CH4) and rich array of hydrocarbons (CxHx) and nitriles (HCN) • Surface – obscured by photochemical haze • Murky atmosphere may be similar to that which existed on Earth before life formed. • Most Earth-like body in the solar system: rivers, lakes, seas, mountains, dunes, channels, winds, volcanos, thick atmosphere - chemically complex

Slide 15: Huygens Separation & Entry Release: December 24, 2004 Decent: January 14, 2005 Data Collection: •Decent: 2h 27m •Surface: 1h 12m •Radiometric: 5h 52m QuickTime™ and a MPEG-4 Video decompressor are needed to see this picture.

Slide 16: The Huygens Descent QuickTime™ and a Sorenson Video 3 decompressor are needed to see this picture.

Slide 17: The Surface of Titan

Slide 18: Arial view of Titan

Slide 19: Huygens “News”

Slide 20: #2: Enceladus

Slide 22: National Geographic, 1981 Slide 22

Slide 24: Enceladus, July 14, 2005 175 km flyby!!

Slide 26: Two UVIS stellar occultations. The one in July identified a local atmosphere around the south pole.

Slide 28: Enceladus Flyby: 12 November 2005

Slide 29: GEYSER COMPOSITION (Waite et al. 2006; Hansen et al., 2006) H2O 91 ± 3 % wt. 2 CO 2 3.2 ± 0.6 % wt. N2 4 ± 1 % wt.* 2 CH4 1.6 ± 0.4 % wt. 4 CO < 0.9 % wt (i.e., (i.e., NH3, HCN, C2H2, C3H8 < 0.5 % wt. (i.e., detected) 3 22 38 *Inferred from a combination of INMS and UVIS data

Slide 30: Why the South Pole? Nimmo and Pappalardo (2006) • Low-density silicate or ice diapir can be sufficient to overcome the equatorial bulge and reorient Enceladus • Resulting stresses may be consistent with the observed tectonic patterns • Few mgal gravity anomaly: might be detectable by Cassini? Slide 30

Slide 31: Planetary Heat Flow Enceladus Avg Earth South Polar Terrain 87 mW/m2 250 mW/m2 Tiger Stripes Yellowstone 13,000 mW/m2 2500 mW/m2

Slide 34: “Mimas Paradox” NASA/JPL/SSI Mimas Enceladus Bistable tidal heating? Diameter 420 km 504 km • Enceladus is warm, dissipative, stays warm. Density 1.2 1.6 • Mimas is cold, rigid, stays Distance from Saturn 3.1 RS 3.9 RS cold. Orbital Eccentricity 0.0206 0.0047 Need a way to “kick start” Tidal heating, solid 16 MW 160 MW Enceladus initially ice rigidity, Q = 20 Slide 34

Slide 35: #3: Titan from Space

Slide 37: Titan: the most Earth-like body in the Solar System detached haze mid-latitude streaks drainage channels huge cloud system mountains river channels wind driven dunes aeolian patterns lakes few craters

Slide 38: ISS map Titan @ 938 nm

Slide 39: VIMS map (r = 5 µm; g = 2 µm; b = 1.6 µm)

Slide 40: RADAR map (TA-T30)

Slide 41: 87°W 20°N Impact basin (above) is 100 km about 450 km in diameter Impact crater (left) is about 80 km in diameter 16°W 11°N Impact Craters Cryovolcano and surface flows

Slide 42: Cat Scratches” = Dunes? Longitudinal Dunes Arabian Peninsula Dunes probably consist of wind-blown hydrocarbon particles

Slide 43: Wispy terrain to east of Shikoku Lucky (Great Britain) resembles dunes seen in earlier SAR data Number 13 Circular feature Guabonito may not be an impact crater after all This complex area of hilly terrain and erosional channels is located atop Xanadu, the continent-sized region QuickTime™ and a Sorenson Video 3 decompressor are needed to see this picture.

Slide 44: A Titan Lake? Cassini had seen several “suspiciously lacustrine features”…

Slide 45: …until finally Cassini found the Titan equivalent of Minnesota.

Slide 47: Titan's Atmospheric Variability mid-latitude streaks Seasonal detached haze changes in 150 km higher weather than observed patterns by Voyager South-polar convective clouds VIMS images of mid-latitude clouds complex, variable haze structure

Slide 48: What Would the INMS Measure in Other Ionospheres? We have discovered that Titan has the most chemically complex ionosphere in the solar system. There are likely strong connections to neutral chemistry; these are still being explored.

Slide 50: #4: Saturn Orbit Insertion and the Rev 28 occultation Images

Slide 51: SOI Trajectory

Slide 52: Saturn Orbit Insertion Ring Plane Crossing QuickTime™ and a Sorenson Video 3 decompressor X are needed to see this picture.

Slide 53: Approach picture from Cassini: May 10, 2004 F Dist: 27 million km. Pixel: 161 km. Moon: Prometheus A C B Cassini ISS image: Space Science Institute (Boulder), NASA/JPL. Encke Gap W~350 km The main rings Cassini Division

Slide 54: Complex Rings QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture.

Slide 56: Rev 28 Occultation

Slide 57: For the first time, we can see all the rings clearly in a single image! D-Ring E-Ring Cassini G-Ring F-Ring Division A-Ring B-Ring C-Ring There is a lot going on in this image, so let’s take a closer look…. No need for these artist’s renditions anymore.

Slide 58: Out here, we see the light scattered by the rings A CD B D C On the planet, we see the light blocked by the rings C B CD A The non-trivial relationship between brightness and amount of material leads to strange images….

Slide 61: Come join us! http://saturn.jpl.nasa.gov